DSET Adopts Shareholder Rights Plan

Bridgewater, NJ - July 23, 2001 - (Nasdaq: DSET) - DSET Corporation announced today that its board of directors has adopted a shareholder rights plan (the "Rights Plan"). Adoption of the plan is not in response to any known effort to acquire control of the company. Under the Rights Plan, each shareholder of record on July 31, 2001 will receive a distribution of one Right for each share of DSET Common Stock ("Rights").

Initially, the Rights will be represented by DSET's Common Stock certificates, will not be traded separately from DSET's Common Stock, and will not be exercisable. The Rights become exercisable only if a person acquires, or announces a tender offer, that would result in ownership of 15% or more of DSET's Common Stock, at which time each Right would enable the holder to buy one one-thousandth of a share of DSET's Series A Preferred Stock at an exercise price of $20, subject to adjustment. The actual number of shares acquirable by the holder equals $20 divided by one-half of the current market price of DSET's Common Stock.

Additionally, the Rights Plan provides that in the event of a subsequent merger or other acquisition of DSET, the holders of Rights will be entitled to buy shares of common stock of the acquiring entity at one-half of the market price of the acquiring company's shares.

Further details of the Rights Plan will be sent to DSET shareholders of record as of July 31, 2001 in early August.


About DSET:

DSET Corporation supplies software and services that enable telecommunications providers to implement electronic Trading Partner Networks, which significantly reduce the time required to provision services for customers and resolve service outages to maintain high service quality and ensure customer retention. DSET is headquartered in Bridgewater, New Jersey, and the company's Web site can be viewed at www.dset.com.

Statements regarding financial matters contained in this press release, other than historical facts, are forward-looking. Since all statements about DSET's plans, estimates, and expectations are based on current projections that involve risks and uncertainties, and are subject to change at any time, the company's actual results may differ materially from expected results. Investors should consider these risks and uncertainties, which are discussed in documents filed by DSET with the Securities and Exchange Commission. These documents identify important factors that could cause the actual results to differ materially from those contained in the projections or forward-looking statements. DSET expressly disclaims any obligation to update any forward-looking statements.

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DSET Contacts:

Financial: Bruce Crowell, Chief Financial Officer, 908-526-7500 Ext. 1775,
e-mail: bcrowell@dset.com

Media Relations: Dean Maskevich, Marketing Communications, 908-526-7500 Ext. 1366,
e-mail: dmaskevi@dset.com

Investor Relations: John P. Murphy, Westfield Investor Relations, 908-233-1558, e-mail: westfieldir@worldnet.att.net

DSET and the DSET logo are registered trademarks of DSET Corporation.

All other trademarks are the property of their respective owners.